(1) Technical Field
The present invention relates to erythromycin derivatives and salts thereof useful as stimulants for contractive motion of the digestive tract, exhibiting action for stimulating contractive motion of the digestive tract of mammals, and also to processes for producing the same.
(2) Background Information
The digestive tract consists of the stomach, the duodenum, the small intestine etc., and plays an important role in the digestion of food taken from the mouth. The contractive motion of the digestive tract is essential in order to perform the digestion smoothly. In a healthy man, the autonomous nerve system and digestive tract hormones function effectively to induce contraction of the digestive tract not only immediately after the intake of foods but also in a state where the digestive tract is empty, when such contraction has been considered absent. The movement in such empty digestive tract is transmitted from the stomach to the duodenum and to the small intestine, and plays an important role cleaning the digestive tract, thus preparing for next intake of foods (Z. Itoh, "Iden", 33, 29, 1979).
A stimulant for contraction of the digestive tract is expected to induce a normal movement of the digestive tract, in a human with weakened function of the digestive tract, thereby a healthy body being maintained.
Motilin is already known as a digestive tract hormone for stimulating the contraction of the digestive tract. This substance is a peptide, consisting of 22 amino acids and extracted by J. C. Brown in 1966 from the mucous membrane of a pig duodenum (J. C. Brown et al., Gastroenterology, 50, 333, 1966), and is already synthesized chemically (E. Wunsch et al., Zeitschrift fur Naturforsch, 28c, 235, 19730.
However the supply of motilin by extraction from natural substance or by chemical synthesis is not sufficient, and has not been possible in a large amount.